On-Demand Hot Water Heaters

It's been a number of years since I was knowledgeable of these. Back then, there were 'brands to buy and brands to stay away from'. And those that didn't play well with pressurized water systems. Etc Etc

Anyone with any recent experience owning one. Larger size for whole house; several bathrooms and several story house? Long runs from heater to bathrooms.

Pros and Cons. Basically I'm just looking at whether a on-demand heater would work and as important does one actually save any money over a standard water heater, all things else being the same.

TIA

I prefer to use smaller "point-of-use" on-demand electric water heaters rather than a large unit for the whole house. The biggest problem I had is with the relatively long runs of pipes that are buried in the walls here because of the type of construction that is done. In areas where you just need a small amount of hot water for a short period of time (kitchen sink, washbasins) I have used with good results small under sink electric units that have a small tank. An example is the Bosch Tronic 3000T Series. They are available in 3 sizes - a 2.7 gal. (ES2.5), 4.0 gal. (ES4) and 7.0 gal. (ES8). They use a standard 127V cord so easy install (the ES8 requires a hard wired connection due to current requirements). I have had an ES4 installed under my kitchen sink for over 2 years and love it.

At the shower heads, I have installed tankless electric heaters since they can run continuously if you want a nice long hot shower. My experience has been with the Bosch Tronic 3000S series. I installed a 7.7 kW one last year (requires 240V) and it works amazingly well. It is slightly oversized so you might consider a lower wattage model that only requires 127V such as the 5.5 kW version. Nice thing with these is they come in a kit with a connector cable and a new shower head so an easy install. Run the outlet from the existing shower head into the unit and the new shower head on the outlet.

Gosolar on TOB recommends Kruger

https://kruger.com.mx/

I think some Kruger models may have a feature that allow integration with a recirc pump for long distance piping runs.

Thank you both, i never think about electric appliances but i have solar SO that would work well for me where i have no accesos to gas.

Personally I do not think electricity and water mix well. If you decide to go Ezzie's route, please make sure the electrical part is done by a qualified electrician and that your electricity is well grounded.

I plan on installing a massive solar system next year and converting everything that is currently gas to electric. Our current gas/elec bill is about $4500p per month.

CBob, do you have a thought as to how many years for payback? At today's prices for elec/gas?,,, knowing full well that those rates will continue to rise?

CanuckBob wrote: Our current gas/elec bill is about $4500p per month.

Wow. Mine is 300 and I don't have solar. That's with one person here about half the time and 2 the other half.

CBob has a pool and two rental units besides his own home. I only have five (350 watt) panels and produce way more than I need. Next I will look into an air conditioning unit for the bedroom along with a submersible pump for the aljibe and I'll still be producing more than I need. Love it!

I priced out solar and it would never pay for itself in my lifetime. If I wanted AC and a pool, it would make sense, but I don't.

And yes, I'm aware that Bob has rental units and that utilities for those would be a business expense. But even if you divide the $4500 by 3 homes, it's still 5 times more energy consumption than what I use.

Although it would be the number of KWHs one uses that determines their consumption, not the bills, if one is paying DAC rates.

RickS wrote:CBob, do you have a thought as to how many years for payback? At today's prices for elec/gas?,,, knowing full well that those rates will continue to rise?

The system I want (12 - 600W panels) will be about $200,000p so about 44 months for payback however I will need to spend another $100,000p or so to convert all my water heaters, stoves and clothes dryer to electric so probably more like 60 months. If CFE keeps raising their rates dramatically it would be sooner....

mudgirl wrote:I priced out solar and it would never pay for itself in my lifetime. If I wanted AC and a pool, it would make sense, but I don't.

And yes, I'm aware that Bob has rental units and that utilities for those would be a business expense. But even if you divide the $4500 by 3 homes, it's still 5 times more energy consumption than what I use.

Although it would be the number of KWHs one uses that determines their consumption, not the bills, if one is paying DAC rates.

Your CFE rates are subsidized on the coast so your cost per khw is lower than where we are. We have a pool, a washer dryer (running every day), 5 TVs, 4 fridges, 7 ceiling fans, a pressure water system, etc. so are in the highest rate category.

Aren't the basic rates subsidized everywhere? (I know the basic rate does vary according to area)
People on the coast here definitely get charged in the no-subsidy DAC rate if they are heavy consumers of electricity, which is why most people here with similar stuff to yours- AC, pools, pressure pumps, etc. put in solar.

Yes they are subsidized but your Tarifa is what determines your rates and, yes, they are different in different areas of the country. I found this to be informative even if it originates on a Playa del Carmen forum. I have Tarifa 01.
https://everythingplayadelcarmen.com/your-cfe-electric-bill-explained-at-last-plus-tips-for-keeping-it-low/
One thing that they didn't mention for keeping down your electrical consumption is roof colour (better to be white if it's flat) and window film for windows which can greatly effect your indoor temperature since it stops heat gain to the interior in hot weather and warm air loss to the exterior in colder temperatures.
Rates for electricity will never go down.
https://mexicobusiness.news/energy/news/cfe-updates-its-electricity-rates-2023

Yes, I use white impermealizante on the roof. I also close my curtains on the sunny side during the day in the summer and vice versa in the winter.

LOL. I can remember sticking my head through the curtains during San Pancho summers and telling the sun to "get the f$%K down".

These days it doesn't even seem to matter much if it's sunny. The "feels like" temp here on the coast has been consistently in the high 90s even in the shade or when it's cloudy if there's no breeze.

3 1/2 yr pay back on my 450 watt@ 12 panel system. Pool, jacuzzi, temazcal, aljibe pump, hot water recirculating pump, fountain pump, and two mini-splits. We would have been in DAC every month if we did not install the solar system.  Pretty much a no brainer in my case.  I have 16 panels now and making about 30% more power than I need but planning for the future.